So I understand compositing at a rudimentary level but when it comes to the compositing done on major films or CG trailers for video-games, I’m struggling to find information that breaks down the process and explains the major relationships.

For example, take a look at the video below from ILM; it’s a visual effects “behind the magic” video that breaks down specific scenes in Star Wars: TFA to show how each element comes together to make a composite image.

Unfortunately, there’s no indication of what is coming together. AO maps? Normal maps? How are they compositing or rendering light in a scene then applying it on a non-lit albedo shot? Is this terminology even correct? I’ve tried looking for videos or articles that breaks down this process in more detail, but all I can find is articles relating to compositing itself (which is helpful!) or just show-reels.

Could anyone give me a general breakdown of the process itself or point me in the direction of a source that can explain it?